Writing Physics Lab Reports. This is a concise
discussion of what is expected in a lab reports for Chabot's
Physics courses. It follows closely protocols laid out here: http://www.physics.upenn.edu/~uglabs/
, page 5 of the Lab Manual (All Courses.) You will generally receive additional information in class.
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and review rules on sig. figs with respect to multiplication ,
division, addition and subtraction, which are important for the lab
write ups. The
lab report,
other than data and graphs, should only be a few pages. Note the
lab handout , including the data sheet, will generally contain all the
elements arranged in the following format; so it's largely a question of
re-arranging the information into the following categories:

(A) COVER SHEET

Must include: name of experiment and date performed; group
partners, individual names and roles; Instructor's name; course and lab
section numbers.

(B) INTRODUCTION/ABSTRACT

#Brief statement (1 paragraph) describing the goals
of the lab and methods/procedure used .Do not merely duplicate the
laboratory handout description.

#Written in a way that a person not familiar with the lab can quickly
understand what the goals and methods used are.

Here is an example of a sentence from an abstract "Using the
electronic picket fence method, we found the acceleration of
gravity to be 9.9 m/s2 + or - 0.9 m/s2.
" Here the goal, or purpose, is clearly to measure the
acceleration of gravity. One could explain briefly the picket fence
method. The absolute uncertainty of 0.9 m/s2 (discussed
below) is quoted.

The statement may be written in terms of a hypothesis. For
example, "The purpose of this experiment is to test the
hypothesis that this resistor obeys Ohm's Law. The results display
a linear relationship between the current and the voltage, Thus,
the hypothesis is true."

(C) DATA : A carbonless copy of all handwritten data must be submitted .Show
units and uncertainties. Should be well organized and arranged in tables
for clarity. Sample printouts of computer generated graphs or tables are
appropriate. Show for example uncertainties in the data points and the uncertainty
in the slope of the best fit line.

If your lab hand out includes a data sheet and graph paper,
include data points and plots here.

(D) ANALYSIS : Outline major calculations and provide an example calculation
for each one. Calculate best values and uncertainties (should be done in
lab to make sure that the data is correct and sufficient). Include
graphs and tables with proper titles and units in sequence or at the end
of the report. State the equations used in calculations and define
all variables.

For example, suppose you measured the acceleration of gravity 6 times --recorded in your data table--see step (C); and suppose your
minimum, average and maximum values were 9.214, 9.7870, and
10.185 m/s2.
You can find the uncertainty of the measurement by taking half the
difference between the minimum and maximum values.
Note there are 5 sig. figs. after I took the average. See class
hand out. The uncertainty in this case is (10.185 - 9.214)/2
= 0.971/2 = 0.4855 m/s2. According to the
rules set down by the Picket Fence lab hand outs , you express your result as
9.7870 m/s2 + or - 4855 m/s2.
If you round the uncertainty to one sig. fig, then the result is
reported as 9.8 + or - 0.5.

These values would
be recorded in your data table (under DATA) and discussed in the ANALYSIS
section.

If your lab hand out includes analysis questions to be answered,
include them here.

(E) SUMMARY/ERROR: Following upon the above-mentioned analysis, a short summary (no more than a few paragraphs)
considering what could have caused error in your measurement. Include
all sources of error (the more insightful the better). Determine the
largest source of error and describe how it could be improved. Explain
possible sources of systematic error that would effect the experiment's
accuracy. Explain possible sources of random error that would effect the
experiment's precision.

(F) CONCLUSION Brief (a few paragraphs). Compare your results to accepted
values. Discuss what the data shows, why, and what you've learned. If
your lab hand out includes a data sheet and tables , include your
comparison here. See sample computation hand out. For example, here you would compute the percent error
between your average value 9.7870 m/s2 and the accepted
value 9.8 m/s2, where
percent error =
(9.7870 - 9.8)*100%/9.8 = (0.013)/9.8*100 %.
= 0 % . We get 0 % since 0.013 has a zero in the 1/10
place, the maximum precision of the accepted value 9.8 . Does the
accepted value (i.e. 9.8 m/s2.) fall within your range based
on the uncertainty? You check this way: The maximum value in the
range is 9.7870 + 0.4855 = 10.2725. The minimum value is
9.7870 - 0.4855 = 9.3015. We see that 9.3015
< 9.8 < 10.2725. Thus, you would answer yes.